Every time some kook shoots somebody or blows up a building for political reasons we are admonished to avoid violence at all costs, avoid divisive speech and in general just be nice. We hear all sorts of talk about violence is never the answer or nothing can be achieved by violence, etc. But is this really true?
The United States would not be an independent country unless it had used violence to secede from England.
Most countries that declare their independence end up having to secure it by means of violence or its threat.
Violence is the system of nature. Lions, sharks, bees, cobras, bulls, hawks, ants, crocodiles, bears, tigers, ad infinitum, protect themselves and enforce their will by violence. Non-violence is a human invention or discovery.
Most of the condemnation of violence always seems to come from those for which violence is their primary tool. The ones who are always wanting to help people by the agency of government - the planners or do-gooders - rely on violence to accomplish their ends. It is private violence that they object to, not violence in principle. Private violence is bad - or maybe even morally wrong - because it obstructs or thwarts their benevolent intentions.
Every time there is an instance of private, i.e. "unauthorized" violence, such as the Arizona Massacre, the left swings into action to try to disarm or restrict the citizen's access to firearms. There is never a similar effort to disarm the police when they kill an innocent person. Government is the greatest practitioner of violence in history, but its actions are explained away by those who wish to justify or support its objectives.
The left needs a violent component to enforce its programs that cannot be implemented by persuasion. Nancy Pelosi, Diane Feinstein or Barack Obama would probably never dream of personally robbing or threatening somebody to support their programs, but they don't mind using the agency of government to do it for them.
A person who thinks this way can coerce the populace to comply with his whim and still pat himself on the back about all that "he's done for the people." It's inconsistent to denounce violence when you routinely employ it to achieve your ends. A man running a protection racket might admire himself for the service he provides his customers - with extorted money - in the same way that a politician admires himself for the health insurance he has forced his constituents to purchase - for their own good. Both of these men are engaged in criminal activity even if the second instance happens to be legal, and both rely on violence to achieve their ends.
The recent trouble in Egypt illustrates how many in the U.S., on both sides of the political spectrum favored using violence against the protesters because Mubarak was "our man" even though the will of the people seemed to favor his removal.
No politician would ever seek the endorsement of the Commissioner of Internal Revenue even though he makes all the politician's benevolent programs possible. Having the Commissioner's endorsement would make it obvious that the programs spring not from an eleemosynary entity, but an extortion racket.
In Book IV of The City of God, St. Augustine asks the question; "Justice being taken away, then, what are kingdoms but great robberies? For what are robberies themselves, but little kingdoms?" He goes on to explain that when a robber band becomes sufficiently large to hold territory and and take on all the attributes of a kingdom, its nature is not changed, but to its covetousness is added impunity - this is the nature of government.
Lord Acton's statement that power tends to corrupt is undoubtedly true, but it is probably the case that power tends to attract those who are already corrupt. Politicians don't become liars and thieves in office, they were mostly liars and thieves before seeking office and their skill at deception facilitates their election. Stealing and lying go together since the thief has to lie to conceal his crime, and stealing is lying in a material form. When you habitually lie and steal, it's handy to have violence as an option, should lies not be sufficient suppress outrage.
The essence of the state is violence, but it is best if this fact can be concealed from the citizens. Occasionally the state bares its teeth and breaks out the fire hoses and police dogs, shoots a few college students or burns down a compound of religious misfits, but it's best if the people continue to believe that government is their servant and they are the masters; not the other way around.